Garage door operators typically include a drive cable assembly trained over a pulley held adjacent the top of the garage door. The assembly often includes a metal chain held by a sprocket at the head unit which includes the motor. While the use of such a chain is generally satisfactory, it is somewhat noisy in operation and is relatively heavy. Furthermore, such a chain drive is difficult to handle during assembly and requires periodic lubrication for optimum performance.
During initial installation, care must be taken to keep the chain taut to avoid kinking. Additionally, because the sprocket teeth must enter the openings formed by the link of the chain, the chain cannot simply be aligned with the sprocket and moved downwardly because the teeth would interfere with the sides of the links. Instead the chain must be pulled past the sprocket teeth and, after alignment, then tightened to pull the chain back into engagement with the sprocket teeth. Simplified installation is always a major objective in a consumer product such as a garage door operator.
Commonly-assigned U.S. Pat. No. 4,885,872, issued Dec. 12, 1989, is directed to a drive belt assembly including a length of reinforced plastic belt having teeth on one side for engaging the teeth on a drive wheel. This patent teaches a connector for joining the belt to other components of the belt assembly, and a shield for holding the belt on the drive wheel. While these components operate satisfactorily, it is always desirable to reduce the number of components, simplify component manufacture, and permit faster assembly and set up of the garage door operator by the installer.